Answer:
Magnitude of impulse, |J| = 4 kg-m/s
Explanation:
It is given that,
Mass of cart 1, 
Mass of cart 2,
Initial speed of cart 1,
Initial speed of cart 2,
(stationary)
The carts stick together. It is the case of inelastic collision. Let V is the combined speed of both carts. The momentum remains conserved.

V = 1 m/s
The magnitude of the impulse exerted by one cart on the other is given by:


J = -4 kg-m/s
or
|J| = 4 kg-m/s
So, the magnitude of the impulse exerted by one cart on the other 4 kg-m/s. Hence, this is required solution.
Answer: 35*10^3 N/m
Explanation: In order to explain this problem we know that the potential energy for spring is given by:
Up=1/2*k*x^2 where k is the spring constant and x is the streching or compresion position from the equilibrium point for the spring.
We also know that with additional streching of 2 cm of teh spring, the potential energy is 18J. Then it applied another additional streching of 2 cm and the energy is 25J.
Then the difference of energy for both cases is 7 J so:
ΔUp= 1/2*k* (0.02)^2 then
k=2*7/(0.02)^2=35000 N/m
Answer:

Explanation:
If
-
,
are temperatures of gasses and liquid in Kelvins,
and
are thicknesses of gas layer and steel slab in meters,
,
are convection coefficients gas and liquid in
,
is the contact resistance in
,
- and
are thermal conductivities of gas and steel in
,
then: part(a):

using known values:
part(b): Using the rate equation :
the surface temperature 
and 
Similarly


The temperature distribution is shown in the attached image
The relationship between resistance R and resistivity

is

where L is the length of the wire and A its cross section.
The radius of the wire is half the diameter:

and the cross section is

From the first equation, we can then find the length of the wire when

(copper resistivity:

)
Answer:

Explanation:
As we know that water from the fountain will raise to maximum height

now by energy conservation we can say that initial speed of the water just after it moves out will be




Now we can use Bernuolli's theorem to find the initial pressure inside the pipe


